1985 GMC 700R4 Trans shifts late won't shift into OD

[mudfish68]

Here we go, I have changed the fluid, changed the gov, checked the TV cable.
everything looks good so far, but when it comes to the internal workings of
the trans I don't have a clue. when I got the vehicle it had been sitting for
3 years but everything was working great. drove it 300 miles and the trans
started to jump from OD to D figured Carb, put new Carb on. Still no good,
then wouldn't up-shift at all except if you rap out the engine and manual
shift. Changed the fluid and filter(both were fine), no differance, changed
the gov, still no help, shifts a little earlier but not much. Still wont
shift to OD. Checked power to in trans, power is good. what do I check next.
HELP! any help would be great....

[Roy Bragg]

I would replace the transmission modulator and vacuum lines to it. It
sounds as though not enough vacuum is reaching the modulator, and the trans
thinks you have the gas to the floor all the time and shifts at higher
speeds.
Roy
"mudfish68" <u46041@uwe> wrote in message news:89dc8b2a1dd34@uwe...
> Here we go, I have changed the fluid, changed the gov, checked the TV
> cable.
> everything looks good so far, but when it comes to the internal workings
> of
> the trans I don't have a clue. when I got the vehicle it had been sitting
> for
> 3 years but everything was working great. drove it 300 miles and the trans
> started to jump from OD to D figured Carb, put new Carb on. Still no good,
> then wouldn't up-shift at all except if you rap out the engine and manual
> shift. Changed the fluid and filter(both were fine), no differance,
> changed
> the gov, still no help, shifts a little earlier but not much. Still wont
> shift to OD. Checked power to in trans, power is good. what do I check
> next.
> HELP! any help would be great....
>